Most fiber optic endoscopes on the market today are made in a conventional manner wherein they include an elongated body or shaft containing both image fibers and light carrying fibers. The endoscope may also have additional passageways for irrigation and/or for conducting operative or investigative procedures. Sometimes it also will be provided with a steering mechanism for pointing the distal end thereof. Most optical endoscopes are configured in a shape to do one specific examination. For example, one may be a flexible cysto-urethroscope for examination of the lower genitourinary tract. Another may be a bronchoscope for looking into the respiratory tract. Still another may be a flexible hysteroscope for looking into the uterus. Once any of these devices is manufactured, it is locked into that configuration and generally can only be used for the purpose for which it was constructed. In other words, it is not adaptable for other types of examinations. An exception to this is that in rare instances one may use a flexible hysteroscope for looking into the bladder. If this is done only because the regular scope is broken or unavailable, or done by mistake. There also is a device now available for looking the nasal sinuses This is a small flexible scope which has an eyepiece, a steering mechanism for changing direction of the device to allow its manipulation into a sinus opening and a light connector. However, it cannot be used for any other purpose.
Because of the necessity for providing a variety of types and styles of endoscopes, the cost invested in endoscopes can be quite high, inasmuch as they are not interchangeable.
U.S. Pat. No. 2,975,785 to Sheldon discloses an endoscope with spaced segments interconnected by two pairs of cables located on opposite sides of the segments. Each pair of cables has distal ends which extend around pulleys mounted on a common shaft which is attached to a handle for rotating the shaft. The rotation of the shaft will cause one of the pairs of cables to be shortened and the other to be lengthened so as to bend the distal end of the endoscope in the desired direction. With the two pairs of cables and control means, the endoscope can be bent in any desired direction.
U.S. Pat. No. 3,266,059 to Stelle discloses a prestressed, articulated joint having pivotal segments which are moved by cables. Associated springs prestress the joint.
U.S. Pat. No. 3,572,325 to Bazell et al., discloses an endoscope with spaced annular segments having control cables extending from the distal end to the proximate end where the cables are connected to a wobble plate which is pivoted to lengthen and shorten the cables to create appropriate bending of the endoscope.
U.S. Pat. No. 3,610,231 to Takahashi discloses an endoscope with a stiff central stay and cables which connect to rotatable elements at the proximate end of the endoscope to alternately lengthen and shorten the cables to deflect the distal end of the endoscope in any direction desired. Again, two pairs of cables are provided which are lengthened and shortened together as an appropriate control mechanism is manipulated.
U.S. Pat. No. 3,799,151 to Fukaumi et al., discloses an endoscope with sections that are pivoted together in series and have wires which can be lengthened and shortened for manipulation of the endoscope to cause bending in any desired direction.
U.S. Pat. No. 4,499,895 to Takayama discloses an endoscope with wires that are lengthened and shortened by means of a motor which rotates in response to movement of a control lever.
Although each of these devices is suitable for its intended purpose, each such device is quite complicated in construction and therefore costly. Also, they are of substantial diameter limiting their use and comfort for the patient.